The invention is directed to a method for setting up a communication connection in a communication network composed of a plurality of network communication nodes and to an address converter for supporting the connection setup.
Communication networks are composed of a plurality of switching nodes networked with one another to which communication terminal equipment are connectible directly or via further devices. Examples of such communication networks are the public switched telephone network (PSTN), data networks or mobile radio telephone networks such as the GSM mobile radio telephone system (Global System For Mobile Communications).
A subscriber of one of these networks has a communication terminal equipment and would like to set up a communication connection to a second communication terminal equipment. To accomplish this, it is necessary to select an operator-specific telephone number in the communication terminal equipment. This operator-specific telephone number serves, for the switching node, as addressing (or symbolic identification) information for the second communication terminal equipment.
Given the likely increase in the plurality of communication networks operating in parallel in the future and the possible switch of a subscriber from one communication network of a network operator to a different communication network of a different network operator, the determination of operator-specific telephone numbers becomes increasingly complex.
EP-A-0 751 691 discloses an intelligent network (IN). Telephone numbers of an area (area code) of the one operator are dialed with TCAP messages and the STP. The operator forwards the call to the intelligent network. A data bank entry is read, and the number has an operator-specific telephone number added to it. The call is subsequently rerouted via a different operator.
Beller, M. J., xe2x80x9cCall Delivery to Portable Telephones away from Home Using the Local Exchange Nethwerkxe2x80x9d Communicationsxe2x80x94Rising to the Heights, Denver, Jun. 23-26, 1991, Vol. 2, pages 948-953, Institute of Electrical and Electronics Engineers, presents a service (800 method) of an intelligent network. Analogous to a 0130 service, a data bank is selected via a service control point (SCP) of an intelligent network. The intelligent network is dialed via a telephone number (service access code, 800). The SCP communicates with a switch via protocols transaction capability application part (TCAP).
Eske-Christensen, B., et al., xe2x80x9cBasis fxc3xcr flexiblere Telecom-Dienstexe2x80x9d, Funkschau, Vol 63, No. 12, May 31, 1991, pages 54-59, discloses an intelligent network (IN). The service user selects the access to the intelligent network, a digital switching technology, with a telephone number (0130). I.e., the service user first selects a service switching point (SSP) with the dialing of the telephone number (0130) in order to use the service of the intelligent network. With this dialing-in, the SSP of the intelligent network communicates a TCAP message to the SCP of the intelligent network. The SCP drives a data bank, and the telephone number that is read out is communicated to the SSP with a TCAP message via the STP (signal transfer point). The SSP subsequently implements the numeral conversion and through-connects the route.
GB-A-2 299 913 likewise discloses an intelligent network. Here, the intelligent network is used in order to enable call re-directions, for example for overloaded long distance connections. A subscriber dials the number of a second subscriber. The call is redirected with TCAP and SCP.
The present invention is therefore based on the object of specifying a method and an address converter (or xe2x80x9csymbol converterxe2x80x9dxe2x80x94the xe2x80x9caddressxe2x80x9d may be construed broadly as any symbolic representation of an identifier) that makes it easier for the calling subscriber to set up a communication connection to a further subscriber. This object is achieved according to the method for establishing a communication link and the address converter described below.
Given the inventive method, a first communication terminal equipment transmits a first address information to a first switching node for setting up a communication connection, whereby first identification features are contained in the first address information. The first switching node interprets the first address information with the first identification features and derives a second address information from it for addressing a first address converter. At least parts of the first identification features are communicated to the first address converter. Second identification features that serve the purpose of addressing a second switching node are generated from the first identification features. The communication connection between the first and second switching node is set up with the second identification features.
The inventive method enables the connection setup even given incomplete address information for operator-specific telephone numbers. Further, the chance of equality between operators of different communication networks is enhanced since subscriber-specific particulars suffice for the connection setup without exact network knowledge.
According to an advantageous development of the invention, the first address converter determines the address of an applicable second address converter from the first identification features, with this second address converter generating at least parts of the second identification features after corresponding signaling. In the sense of an intelligent network, a specialization of the address converters to specific functions can be facilitated, since not all first address converters need maintain a complete data set for the address conversion.
It is thus advantageous that a plurality of first address converters are arranged in the communication network according to geographical points of view. These first address converters are responsible for a specific area in one or more communication networks. These first address converters can be integrated as independent units in the sense of a SCP or in a switching node.
It is also advantageous that a plurality of second address converters are arranged in the communication network according to subscriber-classifying points of view. Such subscriber-classifying points of view are, for example specific services (Fleurop, Emergency Service), specific fields (Hotels) or specific subscriber groups (Siemens employees, residents of a city neighborhood). It is thus possible for independent vendors or operators to achieve improved reachability for such services, fields or subscriber groups.
According to another advantageous development of the invention, the first and/or second address converters are configured as devices of various sub-networks of an overlapping communication network or as independent units in the sense of intelligent networks. These address converters serve as bridges between the networks in the addressing. The expanded addressing can be economically offered when it is made accessible to the calling subscribers of a plurality of communication networks.
The second identification features advantageously contain operator-specific telephone numbers or subscriber addresses. A direct connection setup without further format conversion is thus possible with these second identification features.
The first identification features contain, for example, street addresses or vehicle identifiers of the subscriber of the second communication terminal equipment or other characteristics that can be easily remembered by a person. The structure of the first identification features should assure a fast selection of the address converters and an adequately good limitation for a search algorithm.
An advantageous configuration of the invention provides that the first or second address converter communicates the second identification features for a setup of the communication connection to the first switching node. The function of the address converters can thus be essentially limited to the translation of the addresses and, potentially, a manipulation of the data entries. The address converters can be simply and cost-beneficially realized and can be universally employed at the same time.
Advantageously, a subscriber can modify the identification features of the communication terminal equipment allocated to him. The subscriber is thus given the possibility and the responsibility of himself defining the identification features with which he can be reached or with which he usually has address conversions undertaken given an outgoing call. The rigid allocation of communication terminal equipment and operator-specific telephone number is canceled and a further latitude for configuration is established. For example, a special allocation can be defined short-term for advertising campaigns or the like.
A further advantageous configuration provides that the plurality of and/or the length of the first identification features is classified for a subscriber. A configuration latitude that is limited and can be expanded step-by-step is thus established for the subscriber; this can be connected to predetermined charges. The inventive service can thus be introduced in steps and allows a gradual adaptation to the requirements of the subscriber. When this plurality or, respectively, length is exceeded, a modification of the first identification features is disabled for the subscriber, prevention evasion of the limited latitude for design.
The inventive method allows the conversion between different address types, for example between telephone numbers and E-mail addresses.
It is also advantageous that, when the first switching node determines a format error when interpreting the first address information, a defined address converter is automatically used for interpreting the first address information. Format errors thus do not lead to an abort of the connection setup but can be handled by an address converter that is individually defined for each switching node. The switching nodes in this development need not be equipped for a selection of a suitable address converter.
An advantageous development provides that the first and/or second address converter informs the first switching node or, respectively, the first communication terminal equipment about lacking identification features. The subscriber is thus made aware of problems in the connection setup. Advantageously, the lacking identification features are communicated from the first communication terminal equipment and/or the first switching node to the first and/or second address converter. Valid identification features can be generated in the form of a dialog.
The implementation of the method is simplified when a first identification feature contains a character for a following, incomplete, first address information. Here, the first communication terminal equipment already indicates to the first switching node that an address conversion is necessary. This measure replaces the detection of format errors in the switching nodes.
An advantageous application of the method is a mobile radio telephone network, in which parts of the second identification features describe the address of a home register and of the second communication terminal equipment. In addition to the identification of the second communication terminal equipment, the fast localization thereof and an accelerated connection setup are also supported.